Mitrephora (PROSEA)
Introduction |
Mitrephora (Blume) Hook. f. & Thomson
- Protologue: Fl. ind. 1: 112 (1855).
- Family: Annonaceae
- Chromosome number: x= 9;M. celebicaR. Scheffer: 2n= 18
Vernacular names
- Mempisang (trade name)
- Malaysia: karai (Sabah), pisang-pisang (Peninsular)
- Philippines: lanutan (Filipino).
Origin and geographic distribution
Mitrephora comprises some 40 species occurring from Sri Lanka and India to Indo-China, southern China, Thailand, throughout the Malesian region and in Australia (Queensland). About 25 species are found within Malesia.
Uses
The wood of Mitrephora is used for interior joinery, poles, tool handles, matchboxes and splints, and packing cases. It is suitable for firewood.
In Java M. polypyrena is also cultivated as an ornamental and has been used as cover crop in forest plantations.
Production and international trade
"Mempisang" is a general trade name comprising most of the genera of Annonaceae , and Mitrephora probably comprises only a very minor proportion of the wood traded under this name. In 1992 the export of mempisang wood from Sabah amounted to 25 000 m3of sawn timber and 42 500 m3of logs with a total value of about US$ 7.2 million. Small amounts of mempisang are imported by Japan, mainly from Sabah and Sarawak.
Properties
Mitrephora yields a medium-weight to heavy hardwood with a density of 780-950 kg/m3at 15% moisture content. Heartwood pale yellow-brown, not clearly differentiated from the sapwood; grain straight; texture rather coarse to moderately fine and uneven; wood with silver grain. Growth rings usually indistinct; vessels moderately small to medium-sized, solitary and in radial multiples of 2-4, occasionally in small clusters, mostly open and with chalky white deposits; parenchyma abundant, apotracheal in regular, narrow bands (scalariform); rays moderately fine to medium-sized; ripple marks absent.
The wood is fairly strong and non-durable.
See also the table on microscopic wood anatomy.
Botany
Shrubs or small trees up to 21 m tall; bole fairly straight, up to 40(-50) cm in diameter, without buttresses; bark surface grey; crown irregular with spreading branches. Leaves distichous, simple, entire, leathery, with nearly parallel veins and fine reticulations, exstipulate. Flowers opposite the leaves, solitary or in a few to many-flowered, extra-axillary fascicle, bisexual; sepals 3, valvate, free or connate; petals 6, valvate, in 2 rows, outer ones longer than inner, white or yellowish-green to purple, inner ones distinctly clawed and united at apex; stamens many, with flat-topped connectives; carpels few to many, free, each with 4-many ovules in 2 rows, stigma oblong to curved. Fruit apocarpous, each monocarp stalked or sessile, globose to ellipsoid, hairy. Seedling with epigeal germination; cotyledons emergent, leafy; hypocotyl elongated; leaves arranged spirally on the orthotropic leader, distichous on the branches.
In an open forest in East Kalimantan the mean annual height increment of seedlings of a Mitrephora species, possibly M. lanotan , was 42 cm. In cultivation M. polypyrena flowers throughout the year.
Mitrephora is botanically poorly known and in need of a thorough taxonomic revision.
Ecology
The timber-yielding Mitrephora species are found in primary rain forest, up to 600 m altitude.
Silviculture Mitrephora can be propagated by seed. In a germination test in Peninsular Malaysia seeds of M. maingayi showed about 40% germination in 1-9 months.
Genetic resources and breeding
As the timber-yielding Mitrephora species occur only in primary forest and generally display a comparatively narrow distribution, genetic erosion through deforestation represents a serious threat.
Prospects
Wood properties and silvicultural aspects of Mitrephora are poorly known, indicating that present use is very limited. It probably has very little potential in the near future.
Literature
70, 162, 163, 267, 358, 436, 595, 707, 829, 831, 861, 863, 967, 1017, 1038, 1126, 1134, 1221, 1274.